EP 2657142 A1 discloses a device for applying adhesive labels to the edges of folded products constituting the leading edges in the conveying direction. In the event that a folded product is to be labeled at its trailing edge, when seen in the production direction, EP 2657142 A1 provides a turning device turning the folded product by 180° before it arrives at the labeler, so that it can always be supplied to the labeler with the leading edges coming first, for applying an adhesive label at the leading side.
U.S. Pat. No. 4,160,687 discloses a labeler for applying, by means of sensor-controlled rotating brushes instead of blowing nozzles, adhesive labels to the folded product side constituting the trailing side in the direction of production for folding the label that was previously dispensed onto the upper side of the folded product also onto the bottom side, so as to replace blowing nozzles.